The invention relates to a folder with at least two folding cylinders provided with cooperating folding members in the form of folding blades and, respectively, folding jaws.
In known arrangements of this type the folding cylinders are held at a certain distance from each other so as to leave a fixed gap through which the products to be processed have to pass. The size of gap is in this case adapted to suit the thickness of the product, normally in such a manner that the gap is somewhat undersize in relation to the thickness, such undersize being allowed for by the elasticity of an elastic cylinder cover. This however only leads to satisfactory operation when the product has a certain thickness. If the thickness of the product is less than rated for there is no reliable engagement with the surface of the cylinder. If the product has a greater thickness than envisaged the greater surface pressure will lead to a ruck or pucker in the elastic cover and such ruck or wave may entail displacement of the products. More especially in the case of folders of double width with two production lines placed side by side for products of different thickness severe difficulties may be expected.